System and method for vehicle direction signaling using an accelerometer for cancellation control

ABSTRACT

A direction signaling system ( 12 ) for a vehicle ( 10 ) includes left and right signaling units ( 16-22 ) that are operable for indicating intended turning movements of the vehicle. A module ( 26 ) controls selective operation of the signaling units ( 16-22 ) and controls cancellation of signaling unit operation. The module ( 26 ) includes an accelerometer (e.g.,  38 ) for sensing vehicle acceleration. A processor ( 50 ) of the module ( 26 ) determines if the sensed acceleration is indicative of a need to cancel signaling unit operation and cancels signaling unit operation in response to the determination.

TECHNICAL FIELD

The present invention is related to direction signaling systems forvehicles, and is particularly related to systems that have an automaticcancellation feature for ceasing a turn signal indication.

BACKGROUND OF THE INVENTION

Vehicles, such as motorcycles, have direction signaling systems. Anoperator of a vehicle utilizes a direction signaling system of thevehicle to indicate intended turning movement of the vehicle. Typically,a signaling system includes a manually actuatable selector that isoperated to activate the signaling system to provide either a right turnindication or a left turn indication.

For a vehicle, such as a automobile, with a steering member (e.g., asteering wheel) that is rotated a significant amount (e.g., pluralrotations) to accomplish a steering maneuver, cancellation of a turnindication can easily be accomplished by monitoring steering wheelrotation. Motorcycles typically do not include a steering member thathas such a relatively large range of travel that occurs during asteering maneuver. Often, a steering maneuver on a motorcycle can beaccomplished with little or no movement of a steering handlebar of themotorcycle. Thus, for motorcycles, it is common to have a signalingsystem that requires manual cancellation (i.e., a manual movement of aselector switch).

Also, it is known to utilize a timing mechanism within a directionsignaling system on a motorcycle for canceling a turn indication after apredetermined time period. Further, it is known to use a mechanical tiltswitch within a motorcycle direction signaling system to obtaincancellation of a turn indication. The use of a tilt switch has somemerit because a motorcycle will often be tilted and then returned to anupright orientation during a steering maneuver.

However, the above-mentioned turn indication cancellation features formotorcycles have shortcomings. Reliance upon manual cancellation has theassociated detraction that the operator may forget to manually cancelthe indication. Use of a timer, per se, could result in an indicationperiod that is either less than or greater than a period in which themotorcycle operator wishes the indication to occur. Mechanical tiltswitches may be ineffective in canceling all turn indications. Thiswould be true if the turn is accomplished without sufficient tilting ofthe motorcycle to move a mechanical tilt switch.

SUMMARY OF THE INVENTION

In accordance with one aspect, the present invention provides adirection signaling system for a vehicle. Left and right signaling unitsare operable for indicating intended turning movements of the vehicle.Operation means selectively operate the signaling units. Cancellationmeans cancels signaling unit operation. The cancellation means includesan accelerometer for sensing vehicle acceleration. The cancellationmeans includes means for determining if the sensed acceleration isindicative of a need to cancel signaling unit operation. Thecancellation means includes means for canceling signaling unit operationin response to the determination.

In accordance with another aspect, the present invention provides amethod of direction signaling for a vehicle. Either a left or a rightsignaling unit is selected for operation to indicate an intended turningmovement of the vehicle. The selected signaling unit is operated.Vehicle acceleration is sensed. A determination is made as to whetherthe sensed acceleration is indicative of a need to cancel signaling unitoperation. Signaling unit operation is canceled in response to thedetermination.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the present inventionwill become apparent to those skilled in the art to which the presentinvention relates upon reading the following description with referenceto the accompanying drawings, wherein:

FIG. 1 is a top view of a motorcycle that incorporates a signalingsystem in accordance with the present invention;

FIG. 2 is a function block diagram of the system shown in FIG. 1;

FIG. 3 is a side view of the motorcycle shown in FIG. 1;

FIG. 4 is a flow chart for a process performed within a processor shownin FIG. 2; and

FIG. 5 is a flow chart for another process performed within theprocessor of FIG. 2.

DESCRIPTION OF PREFERRED EMBODIMENT

A vehicle 10 that incorporates a direction signaling system 12 inaccordance with the present invention is shown in FIG. 1. Preferably,the vehicle 10 is a motorcycle 10. Four signaling units 16-22 arelocated on the motorcycle 10. Toward the front of the motorcycle 10 arefront left and right signaling units 16 and 18, respectively. Locatedtoward the rear of the motorcycle 10 are rear left and right signalingunits 20 and 22, respectively. Preferably, each of the signaling units16-22 includes an electrically energizable light bulb that is enclosedwithin a housing that has an amber or red lens.

A module 26 (FIG. 2) of the system 12 selectively provides electricalenergy to the signaling units 16-22 such that the light bulbs areenergized and provide an indication to an observer (not shown) of themotorcycle 10. The module 26 (FIG. 3) is fixed to a mount 28 (e.g., partof a frame) of the motorcycle 10 and electrical energy is provided by apower supply V+ (FIG. 2, e.g., a battery) of the motorcycle. The module26 is shown in FIGS. 1 and 3 in a disproportionate size and at aconvenient location for the purpose of ease of illustration. The sizeand location of the module 26 shown in FIGS. 1 and 3 should not beconstrued as a limitation on the invention.

A selector switch 30 (FIG. 1) is provided on a handlebar 32 of themotorcycle 10 for providing operator input to the module 26. The switch30 may take any suitable form that is manually actuatable by an operator(not shown) to select either a left turn indication or a right turnindication. Also, the switch 30 is manually actuatable to an “OFF”setting wherein neither left nor right indications are provided. In oneexample, the switch 30 has a member that is movable between acenter-neutral “OFF” position, a left position, and a right position. Inanother embodiment, the switch 30 includes a plurality (e.g., three) ofactuatable members that are provided for the operator to select the leftturn indication, the right turn indication, or the cessation of anindication (i.e., the “OFF” setting).

The module 26 (FIG. 2) has means for controlling cancellation of theindication provided by the signaling units. In accordance with thepresent invention, the means for canceling operation include at leastone accelerometer (e.g., 38) that outputs a signal (e.g., 40) indicativeof acceleration of the motorcycle 10. The sensed acceleration isutilized in the control, and particularly cancellation control, ofsignaling unit operation.

In the example shown in the Figures, there are two accelerometers 38 and42 that output respective signals 40 and 44. Each of the twoaccelerometers 38, 42 outputs its respective signal 40, 44 to have asignal characteristic (e.g., voltage, frequency) indicative of sensedacceleration. The first accelerometer 38 (FIG. 1) is oriented to be alateral accelerometer. In other words, the first accelerometer 38 sensesacceleration force (i.e., acceleration to the left or right) along alateral (i.e., left-to-right) axis 46 of the motorcycle 10. The secondaccelerometer 42 is oriented to be a fore-to-aft accelerometer and senseacceleration force (i.e., acceleration forward or rearward) along afore-to-aft (i.e., longitudinal) axis 48 of the motorcycle 10.

In accordance with the present invention, when a sensed acceleration isindicative of a need to cancel signaling unit operation, the module 26cancels signaling unit operation. Turning attention to FIG. 2, detailsof the module 26 are shown. A processor 50 of the module 26 receivesinput 52 from the manual switch 30. The first and second accelerometers38 and 42 are also connected to provide their signals 40 and 44 asinputs to the processor 50.

The processor 50 makes determinations regarding turn signal indicationsand outputs signals 54 and 56 to left and right relay units 58 and 60.The left relay unit 58 is, in turn, operatively connected to the leftsignaling units 16 and 20, accordingly. The right relay unit 60 is, inturn, operatively connected to the right signaling units 18 and 22,accordingly. The relay units 58 and 60 provide for a selective ON/OFFcadence of energizing the light bulbs of the associated left and rightsignaling units 16-22. A timer unit 64 is provided within the module 26to provide default time periods used for operation of the signalingunits 16-22.

When the operator of the motorcycle 10 actuates the switch 30 to input adesired turn indication (e.g., a right turn indication) request, theprocessor 50 provides a signal to the appropriate relay unit (e.g., theright relay unit 60). The processor 50 also commands the timer unit 64to initiate an overall timer function. The overall timer functionoperates to terminate the signal indication after a predetermined (e.g.,preprogrammed) time period. In one embodiment, the predetermined amountof time associated with the overall timer function is slightly greaterthan the expected time within which a turn maneuver is to be completed.

Once the operator actuates the switch 30 to input the desired turnindication request and the overall timer is proceeding, the processor 50begins to monitor the acceleration indicative signals 40 and 44 providedby the first (lateral) accelerometer 38 and the second (fore-to-aft)accelerometer 42. In particular, if the lateral acceleration rises abovea predetermined threshold value (herein referred to as a turnthreshold), the processor 50 interprets the lateral acceleration rise asan indication that the turn maneuver has begun. Subsequently, if thelateral acceleration falls below the turn threshold, the processor 50interprets the reduction in lateral acceleration as an indication thatthe turn maneuver is proceeding toward conclusion.

In response to the indication that the turn maneuver is proceedingtoward conclusion, the processor 50 commands the timer unit 64 toinitiate an after-turn timer function such that the turn signalindication will soon be terminated. Specifically, the after-turn timerfunction provides for a relatively short time period within which theturn indication is continued and then canceled (i.e., terminated) uponexpiration of the time period provided by the after-turn timer function.Thus, the cancellation of the turn indication is responsive to thereduction in lateral acceleration (as an indication that the turnmaneuver is proceeding toward conclusion), but the system 12 awaitsconclusion of the short time period before the actual cancellation ofthe turn indication occurs.

However, if the acceleration signal 44 provided by the second(fore-to-aft) accelerometer 42 indicates acceleration above a certainthreshold value, the processor 50 stops or stays the after-turn timerfunction (i.e., the after-turn timer does not decrement). Such acondition occurs when the motorcycle 10 is accelerated forward. The stayof the after-turn timer function ceases once the fore-to-aftacceleration falls below the certain threshold value.

Eventually, once the after-turn timer has proceeded to expiration (e.g.,the after-turn timer has decremented down to zero), the turn indicationis cancelled. Similarly, if the overall timer has eventually proceededto expiration (e.g., decremented down to zero), the turn indication iscancelled. Thus, the overall timer function provides a back-up to theacceleration-based cancellation of the indication.

Of course, the operator has the option of terminating a turn indicationby merely actuating the switch 30 to the “OFF” setting. In a preferredembodiment, the turn indication ceases immediately when the operatoractuates the switch 30 the “OFF” setting. Any unexpired timers aremerely ignored and reset as needed.

An example turn indication provision and cancellation control process100 performed by the processor 50 is shown in a flow chart of FIG. 4.The process 100 begins at step 102 and proceeds to step 104. At step104, it is determined whether the switch 30 has been manually actuatedfrom the “OFF” setting to either the left or right setting. If thedetermination at step 104 is negative (the operator has not actuated theswitch 30 to request a turn indication), the process 100 continues toloop and perform step 104. However, if the determination at step 104 isaffirmative (i.e., the operator has actuated the switch 30 as a requestto provide an indication), the process 100 proceeds to step 106.

At step 106, the overall timer function of the timer unit 64 isinitiated. At step 108, lateral acceleration, as indicated by the signal40 from the first accelerometer 38), is monitored to determine if thelateral acceleration exceeds the turn threshold. If the determination atstep 108 is negative, the process 100 proceeds to step 110 to determineif the overall timer has expired (i.e., timed-out). If the determinationat step 110 is negative (i.e., the overall timer has not yet expired),the process 100 loops back to step 108.

If the determination at step 108 is affirmative (i.e., the lateralacceleration is above the turn threshold), the process 100 proceeds tostep 112. At step 112, it is determined whether the lateral accelerationhas fallen below the turn threshold (i.e., the turn maneuver is ending).If the determination at step 112 is negative (i.e., the lateralacceleration is still above the turn threshold), the process 100continues to repeat the step 112. However, if the determination at step112 is affirmative (i.e., the lateral acceleration has fallen below theturn threshold), the process 100 proceeds to step 114.

At step 114, the after-turn timer is started. At step 116, it isdetermined whether the forward acceleration, as indicated via the signal44 from the second accelerometer 42, is above the predeterminedthreshold. If the determination at step 116 is affirmative (i.e., theforward acceleration is above the threshold), the process 100 loops backto repeat step 114. In other words, the after-turn timer is restarted.This has the affect of staying performance (i.e., waiting) for a periodbefore permitting the after-turn timer to proceed toward expiration(e.g., decrementing to zero).

When the determination at step 116 is negative (i.e., the forwardacceleration is below the associated threshold), the process 100proceeds to step 118. At step 118, the after-turn timer is permitted toproceed toward expiration. Upon completion of step 118, the process 100proceeds to step 120 where the turn indication is cancelled. A similarresult will occur if step 110 is reached and the determination at step110 is affirmative (i.e., the overall timer has decremented down tozero). Upon completion of step 120, the process 100 loops to step 104 toagain make a determination regarding switch activation.

It is to be appreciated that in the example process shown in FIG. 4, theactuation of the switch 30 to the “OFF” setting acts as an interrupt. Atany point during the process 100, if the switch 30 is actuated “OFF”,the turn indication that currently is occurring is terminated and theprocess 100 stops. The process 100 then restarts at step 102. It is tobe understood that the flow chart shown in FIG. 4 could show additionalsteps of determinations regarding actuation of the switch 30 to the“OFF” setting to accomplish the same concept of terminating the currentturn indication.

As an additional feature provided by the system 12 of the presentinvention, fore-to-aft acceleration is utilized to provide additionalsignaling. Specifically, signaling other than left and right turnindications is provided in response to certain sensed fore-to-aftacceleration. In the example set forth herein, the system 12 providesfor an indication of deceleration of the motorcycle 10 that exceeds apredetermined threshold. A determination of deceleration exceeding thepredetermined threshold is made within the processor 50 via monitoringthe signal 44 output by the second (fore-to-aft) accelerometer 42.

When the motorcycle is experiencing deceleration above the predeterminedthreshold, the rear left and right signaling units 20 and 22 providesignal indications other than turn indications. Examples of indicationsfor deceleration include simultaneous illumination or simultaneousflashing (i.e., alternating ON and OFF).

FIG. 5 is a flow chart of an example of a process 200 that is performedwithin the processor 50 for providing the deceleration indications.Preferably, the process 200 would cooperate, and be performed inconjunction, with the process 100 of FIG. 4. The process 200 (FIG. 5)begins at step 202, and proceeds to step 204. At step 204, it isdetermined if the sensed deceleration, as indicated by the signal 44from the second accelerometer 42, is above a predetermined thresholdvalue.

If the determination at step 204 is negative (i.e., deceleration of themotorcycle is below the predetermined threshold value), the process 200repeats step 204. If the determination at step 204 is affirmative (i.e.,deceleration is above the predetermined threshold value), the process200 proceeds to step 206. At step 206, it is determined if a turnindication is currently in progress (i.e., determine whether the leftsignaling units 16, 20 or the right signaling units 18, 22 are beingenergized in the ON/OFF cadence).

If the determination at step 206 is negative (i.e., a turn indication iscurrently not in progress), the process 200 proceeds to step 208. Atstep 208, both (i.e., left and right) rear signaling units 20 and 22 areenergized. Preferably, the energization is continuous (i.e., steadystate and not an ON/OFF cadence), similar to a brake light. Thisprovides a warning to an observer following the motorcycle 10 that themotorcycle is decelerating.

At step 210, it is determined whether the deceleration of the motorcycle10 has dropped below the predetermined threshold value. If thedetermination at step 210 is negative (i.e., the motorcycle 10 is stillexperiencing deceleration above the threshold), the process 200 repeatsstep 210 and the deceleration indication is maintained. If thedetermination at step 210 is affirmative (i.e., the motorcycledeceleration has dropped to below the threshold), the process 200proceeds to step 212 where the deceleration indication is terminated.Upon completion of step 212, the process 200 loops to step 204 to againmake a determination regarding motorcycle deceleration.

If the system 12 had been providing a turn indication at the time thatmotorcycle deceleration exceeded the predetermined threshold, thedetermination at step 206 would be affirmative. Upon the affirmativedetermination at step 206, the process 200 proceeds to step 214. At step214, the rear signaling unit that is not currently providing a turnindication (i.e., the non-flashing signaling unit) is energized. Theenergizing is preferably an ON/OFF cadence, thus, both signaling unitsare providing a “flash” ON and OFF. This provides an indication ofmotorcycle deceleration and also that a turn is anticipated.

At step 216, it is determined whether the motorcycle deceleration hasdropped below the predetermined threshold value. If the determination atstep 216 is negative (i.e., the motorcycle is still experiencingdeceleration above the threshold), the process 200 repeats step 216 andthe deceleration indication is maintained. If the determination at step216 is affirmative (i.e., the motorcycle deceleration has dropped tobelow the threshold), the process 200 proceeds to step 218 where therear signaling unit ceases to be energized to provide the decelerationindication. Upon completion of step 218, the process 200 loops to step204 to again make a determination regarding deceleration.

From the above description of the invention, those skilled in the artwill perceive improvements, changes and modifications. Suchimprovements, changes and modifications within the skill of the art areintended to be covered by the appended claims.

Having described the invention, the following is claimed:
 1. A directionsignaling system for a vehicle, said system comprising: left and rightsignaling units operable for indicating intended turning movements ofthe vehicle; operation means for selectively operating said signalingunits; cancellation means for canceling signaling unit operation, saidcancellation means including a first accelerometer for sensing vehicleacceleration along the lateral axis, means for determining if the sensedacceleration is indicative of a need to cancel signaling unit operation,and means for canceling signaling unit operation in response to thedetermination; and modification means for modifying the operation of thesignal unit, including a second accelerometer, means for mounting saidaccelerometer to sense acceleration along a fore-to-aft axis, means fordetermining if the sensed acceleration along the fore-to-aft axis isindicative of a need to modify signal unit operation, and means formodifying signaling unit operation in response to the determinationrelating to sensed fore-to-aft acceleration.
 2. A direction signalingsystem as set forth in claim 1, wherein said accelerometer includesmeans for outputting a signal that has a characteristic that varies inresponse to sensed acceleration.
 3. A direction signaling system as setforth in claim 1, wherein said means for determining includes means formonitoring the signal characteristic.
 4. A direction signaling system asset forth in claim 1, wherein said cancellation means includes means forawaiting a time period in response to the determination that the sensedacceleration is indicative of a need to cancel signaling unit operation,said means for canceling also being responsive to said means forawaiting to delay canceling signaling unit operation during awaiting thetime period, said means for modifying signaling unit operation inresponse to the determination relating to sensed fore-to-aftacceleration includes means for changing a length of the time period. 5.A direction signaling system as set forth in claim 1, including meansfor determining if the sensed acceleration along the fore-to-aft axis isindicative of a need to provide a warning, means for operating saidsignaling units to provide a warning in response to the determination ofthe need to provide the warning.
 6. A direction signaling system as setforth in claim 5, wherein said means for determining if the sensedacceleration along the fore-to-aft axis is indicative of a need toprovide a warning includes means to determine of the sensed accelerationalong the fore-to-aft axis is indicative of a vehicle deceleration abovea predetermined threshold, said means for operating said signaling unitsto provide a warning includes means for operating both signaling unitsto provide the warning.
 7. A method of direction signaling for avehicle, said method comprising: selecting either a left or a rightsignaling unit for operation to indicate an intended turning movement ofthe vehicle; operating the selected signaling unit; sensing vehicleacceleration along its lateral axis; determining if the sensedacceleration is indicative of a need to cancel signaling unit operation;canceling signaling unit operation in response to the determination;sensing vehicle acceleration along the fore-to-aft axis; determining ifthe sensed acceleration along the fore-to-aft axis is indicative of aneed to modify signaling unit operation; and modifying signal unitoperation in response to the determination relating to the sensedfore-to-aft acceleration.
 8. A method as set forth in claim 7, includingawaiting a time period in response to the determination that the sensedacceleration is indicative of a need to cancel signaling unit operationand canceling signaling unit operation after the time period.
 9. Amethod as set forth in claim 7, said step of sensing vehicleacceleration includes outputting a signal, that has a characteristicthat varies in response to sensed acceleration, from an accelerometer.10. A method as set forth in claim 9, said step of determining includesmonitoring the signal characteristic.
 11. A method as set forth in claim7, including determining if the sensed acceleration along thefore-to-aft axis is indicative of a need to provide a warning, andoperating the signaling units to provide a warning in response to thedetermination of the need to provide the warning.